Spectrum scarcity has resulted in the demand for technologies which can make more efficient use of allocated bandwidths.
Multiple Input Multiple Output (MIMO) technology is reported to be such a technology, one which attempts to exploit multipath propagation effects to provide higher data throughput, whilst remaining spectrally efficient.
The generic term MIMO is sometimes used to refer to a number of technologies relating to multiple antennas. These include so-called “Spatial Multiplexing”, in which multiple signals are transmitted over the same resources (Implemented in Wideband Code Division Multiple Access (WCDMA) as Double Transmit Antenna Array (D-TxAA)), “Transmit Diversity”, in which the same information is transmitted over multiple channels (WCDMA example TxAA) and beamforming techniques.
By definition, spatial multiplexing MIMO technology works with multiple signals, the generation of which will lead to more user and system interference. Receivers working in such scenarios are likely to be more complex as a consequence. Current 3GPP WCDMA standards make use of all of these types of MIMO in the downlink (for example Transmit Diversity, TxAA, and Double Transmit Adaptive Array, D-TxAA, for High Speed Downlink Packet Access (HSDPA)). Such MIMO schemes can improve throughput in the downlink.
The following documents of the 3GPP WCDMA standards can be considered as a basis for the invention.
The document TS 25.211 of the 3rd Generation Partnership Project (3GPP); Technical Specification Group Radio Access Network; Physical channels and mapping of transport channels onto physical channels (FDD), v8.2.0, 2008-09, Release 8, may describe the characteristics of the Layer 1 transport channels and physicals channels in the FDD mode of UTRA. The main objectives of the document may be to be a part of the full description of the UTRA Layer 1, and to serve as a basis for the drafting of the actual technical specification.
The document TS 25.212 of the 3rd Generation Partnership Project' (3GPP); Technical Specification Group Radio Access Network; Multiplexing and channel coding (FDD), v8.3.0, 2008-09, Release 8, may describe the characteristics of the Layer 1 multiplexing and channel coding in the FDD mode of UTRA.
The document TS 25.213 of the 3rd Generation Partnership Project (3GPP); Technical Specification Group Radio Access Network; Spreading and modulation (FDD), V8.2.0, 2008-09, Release 8 may describe spreading and modulation for UTRA Physical Layer FDD mode.
The document TS 25.214 of the 3rd Generation Partnership Project (3GPP); Technical Specification Group Radio Access Network; Physical layer procedures (FDD), V8.3.0, 2008-09, Release 8, may specify and establish the characteristics of the physicals layer procedures in the FDD mode of UTRA.
The document TS 36.211 of the 3rd Generation Partnership Project (3GPP); Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical Channels and Modulation, v8.4.0, 2008-09, Release 8, may describe the physical channels for evolved UTRA.
The document TS 36.212 of the 3rd Generation Partnership Project (3GPP); Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding, V8.4.0, 2008-09, Release 8, may specify the coding, multiplexing and mapping to physical channels for E-UTRA.
The document TS 36.213 of the 3rd Generation Partnership Project (3GPP); Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA), v8.4.0, 2008-09, Release 8, may specify and establish the characteristics of the physicals layer procedures in the FDD and TDD modes of E-UTRA.
The document TS 36.214 of the 3rd Generation Partnership Project (3GPP); Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer—Measurements, v08.4.2, 2008-09, Release 8; may contain the description and definition of the measurements done at the UE and network in order to support operation in idle mode and connected mode.